CF.sub.3 H is useful as a precursor for the formation of tetrafluoroethylene, which can be polymerized to polytetrafluoroethylene. CF.sub.4 is useful for a plasma activating agent in the semiconductor industry. Heretofore, these compounds have been made in high yields as desired reaction products in two process steps: first a chlorinated intermediate is formed, e.g. starting from methane, followed by fluorination of this intermediate. Thus, CCl.sub.4 has been reacted with HF to obtain CF.sub.4. Example 4 of U.S. Pat. No. 3,258,500 discloses the reaction of HF with CCl.sub.3 H to make CF.sub.3 H; this is the second process step. Synthesis of the CCl.sub.3 H starting material is the first process step. U.S. Pat. No. 3,652,692 discloses reacting CH.sub.4 with Cl.sub.2 in a first step to form chloromethanes, followed by reacting the chloromethanes with HF.
Chlorofluoromethanes have been made in one-step by simultaneously reacting CH.sub.4 with Cl.sub.2 and HF. See U.S. Pat. Nos. 2,407,129, 3,294,852, and 3,442,962.
British Patent 1,017,152, discloses the reaction of CH.sub.4 with Cl.sub.2, and HF in the presence of a large proportion of halogenated hydrocarbon. The major reaction products disclosed are CF.sub.2 Cl.sub.2 and CFC.sub.3. Example 10 also discloses CF.sub.3 H as a small amount of reaction product and CCl.sub.4 as a major reaction product when large proportions of CCl.sub.3 H and CHFCl.sub.2 precursors to CF.sub.3 H were present in the halogenated hydrocarbon feed to the reaction. U.S. Pat. No. 3,258,500 discloses CCl.sub.3 H to be a precursor for CF.sub.3 H and U.S. Pat. No. 3,652,692 discloses the presence of CHFCl.sub.2 in the reaction of chloromethane with HF to form CF.sub.3 H in the second step of the process.